Earth acts as a giant particle accelerator, creating the dangerous Van Allen radiation belts
One of the many, many worries people had when first sending humans to the Moon had to do with the Van Allen radiation belts. These are layered, two-lobed areas of space around the Earth that have an unusually high density of high-energy charged particles, including electrons. These electrons damage electronics, penetrating deep into a spacecraft and often causing harmful releases of energy in semiconductors or electrical relays. When the Apollo missions sent humans through these belts of space, NASA simply had no idea what to expect since prior human flights had never gone far enough out to cross the fields. The astronauts zipped through unharmed, however, and today the Van Allen belts aren’t thought to pose a significant danger to living things so long as they are shielded and don’t spend too long inside.
However, even after all that, we still had no clear understanding of why the belts were so dangerous to electronics — an invisible force appeared to be ramping up these charged particles to nearly the speed of light, but where was that force coming from? We eventually developed two competing theories, one which said the source of accelerating energy was foreign, the other arguing that it was local. We know the particles mostly come from gusts of solar wind, but is there something intrinsic to our area of space that gives the particles a boost? This week the journal Science published the answer: it’s the Earth’s own magnetic field that makes the Van Allen belts so dangerous.
The cause, it seems, are lower-energy electrons that give off just the right frequency of electromagnetic radiation, in this case in the radio portion of the spectrum. It’s a powerful enough source of energy to be detectable with a hand-held antenna and headphones, though that can’t be too surprising given the level of energy it can impart to particles in the Van Allen belts. Lead researcher Geoffrey Reeves likens the effect to hitting a tether ball: “The waves have just the right frequency to hit that tether ball each time it comes around, at just the right time, so it goes faster.” Eventually, these electron tether balls approach relativistic speeds.
For decades it was believed that Earth had only two Van Allen belts, but just a few months ago the Van Allen probes discovered a third, much farther out than the first two. It turned out to be transient, eventually being blown away by a strong solar shockwave. Still, as we become increasingly dependent on global communications technology, a detailed understanding of these belts of space will become more important. Everything from GPS satellites to research telescopes shield their electronics and generally shut down when entering them to minimize the chance of damage.
Even then, solar storms and local geomagnetic phenomena can swell the fields dramatically, sometimes engulfing whole fleets of satellites with little warning. It’s only recently that scientists have truly appreciated how volatile these fields of space can be. Right now, their changes are often unpredictable — but this breakthrough might help us change that. Understanding the nature of the the space around our planet will be critical to predicting its actions.
Interestingly, there is a proposition to actually destroy the Van Allen belts with a program called the High Voltage Orbiting Long Tether (HiVOLT). This system of five 100 kilometer-long charged tethers would be deployed from satellites and magnetically deflect the charged particles. This would disburse them remarkably quickly, with projections putting the electron flux at just 1% of today’s level after two months of operation.
Regardless, understanding the Van Allen belts will be necessary if want to have any hope of continuing to advance our mechanization of the skies at the current pace.
Research paper: doi:10.1126science.1237743 – “Electron Acceleration in the Heart of the Van Allen Radiation Belts”
NASA’s Solar and Heliospheric Observatory (SOHO) has captured images of an unusually large coronal hole on the surface of the Sun. At one point, it was so large that it covered nearly a quarter of the Sun’s visible disk — a distance equivalent to 50 Earths placed side-by-side.
As dramatic as this sounds, coronal holes are nothing to worry about. The phenomenon happens every 11 years as the solar cycle comes to an end and the Sun attains its solar maximum — a regularly occurring event in which the magnetic fields on the Sun reverse and new coronal holes appear near the poles with the opposite magnetic alignment.
Photo: ESA & NASA/SOHO. Taken on July 18.
These holes are dark, low density regions located in the outermost region of the atmosphere. They contain little solar material and are significantly cooler than their surroundings, which gives them their darker appearance.
According to NASA, coronal holes can influence some aurora on Earth. After magnetic forces open them up, they spew solar material at roughly twice the speed found on other parts of the solar surface.
|See updates below | In case you haven’t heard about it, a huge
chunk portion of the sun’s corona has indeed gone missing. But even if you have heard about this so-called “coronal hole,” click on the screenshot above. It’ll take you to a new animation of the phenomenon posted to the web today by NASA. It’s really dramatic.
| Update 7/31/13: After posting this piece, I had second thoughts about my use of the word “chunk” in the original headline (which read “Why is a Huge Chunk of the Sun Missing”) and in the first paragraph. A huge portion of the sun’s corona, or outer atmosphere, has indeed gone missing. (See the explanation below.) But the word “chunk” implies that a really thick piece of the sun is gone. That’s not true. So I’ve changed the headline and the first paragraph to reflect this. |
The animation consists of images sent back to Earth by NASA’s Solar & Heliospheric Observatory spacecraft, or SOHO. The large, roughly triangular dark area is the coronal hole.
The animation above dates to July 16th. Click here to see another animation, covering July 20-22.
Corey Powell, who writes the awesome “Out There” blog here at Discover, was interviewed about the phenomenon today on the Fox News program America’s Newsroom. Check out the interview in its entirety here.
Corey’s money quote:
You’ll notice that part of the sun is missing . . . This part that’s missing, the reason it’s dark, is that whole chunk of the sun basically ripped off, blew out and is coming our way at about 2 million miles an hour.
Some explanation: The sun can develop a coronal hole when a portion of its magnetic field fails to loop back onto the surface, as it usually does. This allows more solar material to escape into space. In other words, it makes the solar wind even windier. That’s the stuff that’s flying out into space. The region looks dark because there’s simply less hot and bright solar material left behind.
Corey was quick to point out that formation of coronal holes isn’t unusual. But to be sure, this one is larger than most. Measured from one side to the other, the hole is about 80 times as wide as the Earth. “So this is an incredible chunk of the Sun that’s flying out,” he said.
Earth is shielded from the material in the solar wind by it’s magnetic field. But when solar material hits the field, it can jostle it in a way that causes disruption to satellites, power lines and industrial equipment. And sometimes that disruption can be pretty severe.
Not to worry. I checked the forecast from the Space Weather Prediction Center from today (July 30), and nothing terribly dramatic appears to be in store, at least for the next few days:
The geomagnetic field is expected to be at quiet levels on days one and two (31 Jul, 01 Aug) and quiet to unsettled levels on day three (02 Aug).
Sun Opens Explosive Plasma ‘Arms’ in Solar Eruption (Video)
A sun-watching spacecraft spotted our closest star opening its arms to the cosmos. Two strands of plasma from an eruption in the sun’s atmosphere were captured in observations with NASA’s STEREO A satellite.
The plasma arms broke out from a sunspot in a 12-hour-long event that occurred from July 21-22, 2013, according to NASA. The solar phenomenon was observed in a wavelength of extreme UV light and condensed into a time-lapse video.
STEREO A and its sister spacecraft STEREO B launched in 2006 as part of NASA’s Solar Terrestrial Relations Observatory. They are just two of the space agency’s satellites tasked with monitoring the sun’s activity. There’s also the long-lived Solar and Heliospheric Observatory, or SOHO, which launched in 1996 and recently spotted a gigantic hole covering nearly a quarter of the atmosphere over the sun’s north pole.
The sun is currently reaching its 11-year peak in activity, known as the solar maximum. During this period, there are more sunspots causing a boost in solar flares and ejections, though this cycle is shaping up to be the weakest in a century, scientists have said.
Former CIA Director Woosley warns of dangerous EMP threats to America (Video)
President Bill Clinton’s former Director of Central Intelligence, R. James Woolsey, led a panel discussion on Monday on the growing and imminent threat of a natural or nuclear electromagnetic pulse (EMP) by U.S. enemies to the U.S. electrical grid and other critical infrastructures that are largely unprotected.
The event was sponsored by the newly established EMP Coalition, in coordination of the Center for Security Policy, of which Mr. Woolsey is the Honorary Co-Chair along with former House Speaker Newt Gingrich.
Ambassador Cooper had led the strategic arms control negotiations with the USSR under President Reagan and served as the Director of the Strategic Defense Initiative Organization under President George H.W. Bush. Presently, he is the Chairman of High Frontier, an organization dedicated to protecting the United States from nuclear attack.
Dr. Pry served on the Congressional EMP Threat Commission, as a professional staff member on the House Armed Services Committee and as an analyst in the CIA. He is now the Executive Director of the Task Force on National and Homeland Security, a congressional advisory board dedicated to national resiliency in the face of EMP and other threats.
In the little over an hour program, Mr. Woolsey warned that the sun can inflict localized EMP disasters, like the 1989 Hydro-Quebec geomagnetic storm that blacked out eastern Canada, causing billions of dollars in economic losses. He noted that a recent study by insurance industry leader Lloyds of London estimated that if the 1989 Geo-storm struck the east coast of the United States, 20 to 40 million Americans might be blacked out for as long as two years.
A rare geomagnetic super-storm, like the 1859 Carrington Event, would collapse electric grids and life-sustaining critical infrastructures everywhere on Earth, putting at risk the lives of billions.
“Scientists estimate that the world is overdue for another Carrington Event, and the Sun has already entered its solar maximum that shall last through 2013, when a catastrophic Geo-storm is more likely to occur,” Woolsey reported.
Mr. Woolsey also warned that an EMP catastrophe may also be imminent from terrorists and/or rogue states armed with nuclear weapons.
“North Korea already has nuclear missiles, Iran nearly so, and these two are actively collaborating. A single nuclear weapon detonated at high-altitude over this country would collapse the electric grid and other critical infrastructures and endanger the lives of millions,” said Woosley.
Woolsey also emphasized that the hundreds of electric utilities in the United States have thus far not acted to protect themselves from EMP, and cannot be expected to do so voluntarily as national defense and homeland security is a U.S. government responsibility. Woolsey urged that government regulation, by passage of the Secure High-voltage Infrastructure for Electricity from Lethal Damage (SHIELD) Act now before Congress, is necessary to protect the national electric grid.
Ambassador Cooper in the video warned that North Korea may already have the capability to make a catastrophic EMP attack on the United States. On December 2012, Cooper said, North Korea used its so-called Space Launch Vehicle like a Fractional Orbital Bombardment System – a secret weapon invented by the Russians during the Cold War to deliver a stealthy nuclear attack on the United States by orbiting a nuclear weapon over the south polar region, bypassing U.S. Ballistic Missile Early Warning radars (BMEWs) and missile defenses.
Furthermore, Dr. Pry warned that that a disturbing confluence of events suggests an EMP attack might be imminent. Pry stated that thousands of cyber attacks using computer viruses and hacking are probing the defenses of U.S. critical infrastructures, searching for weaknesses.
Pry noted that recently, in April, a sabotage attempt was made against electric grid transformers near San Jose, CA, that damaged five transformers with fire from AK-47 assault rifles.
The act of sabotage attack on the electrical grid was largely not covered by the mainstream media. The vandals also severed fiber optic cables which knocked out some 911 services.
All of the panelists endorsed the SHIELD Act and urged that the Department of Homeland Security develop a new National Planning Scenario focused on EMP, and encouraged other states to follow the example of Maine, not wait for Washington, but pass state initiatives to protect their electric grids from EMP now.
- Security Threats
- CIA Study
- Infrastructure Issues
Solar storms can junk up our technology, new NASA satellite may help thwart them
NASA’s newest telescope is giving scientists their clearest pictures yet of the sun’s atmosphere, and in doing so could help mitigate the potentially devastating effects an extreme solar storm could have on our power and communications networks on Earth.
Launched a month ago, the Interface Region Imaging Spectrograph, or IRIS, on Thursday sent some of its first images of the sun back to Earth. The pictures should help scientists form a better understanding of the sun’s weather, which is important because its influence on Earth goes well beyond providing sunlight and warmth.
An ever-changing pattern of instability on the sun’s surface causes particles to be thrown outward, sometimes directly toward the Earth. These eruptions can take the form of solar flares, which cause the awe-inspiring northern lights, but can also cause the Earth’s atmosphere to expand and increase the amount of drag on low-Earth-orbit satellites, such as those used for spying and GPS navigation, shortening their lifespan.
The most violent eruptions can have a much larger impact, including potentially knocking power grids offline and leaving millions without electricity. Such an eruption occurred in 1859, frying parts of the international telegraph system, which at the time was the main medium for long-distance communications.
If such an event occurred today, with electricity and Internet communications such a fundamental part of daily life, it’s hard to even fully imagine the potential impact. A recent report from Lloyds of London suggested the damage from a violent eruption could leave 20 million people without power for as long as two years.
All solar weather travels through the lower solar atmosphere, and IRIS contains a powerful spectrograph that will focus on this region of the sun. Thus, scientists hope IRIS will give them a better understanding of these solar events and perhaps help them find a way to predict them.
“These beautiful images from IRIS are going to help us understand how the sun’s lower atmosphere might power a host of events around the sun,” Adrian Daw, mission scientist for IRIS at NASA’s Goddard Space Flight Center, said in a statement. “Any time you look at something in more detail than has ever been seen before, it opens up new doors to understanding. There’s always that potential element of surprise.”
The Earth is prone to the impact of solar weather because the particles hitting Earth from the sun are magnetized.
“When that magnetic field hits the Earth’s magnetic field, we have two magnetic fields interacting and you create electrical currents,” said Karel Schrijver, a senior fellow at Lockheed Martin Space Systems’ advanced technology center in Palo Alto, California. Lockheed Martin built the spectrograph that lies at the heart of IRIS’ observations of the sun.
The electrical currents will run through any conductor on Earth, Schrijver said, and have their greatest effect on high-voltage power lines that sit at the heart of the electric grid. The lines are like inter-city freeways for electricity, carrying power across vast distances at voltages as high as 765,000 volts. Large transformers are used to “step down” the voltage where the lines connect with regional distribution systems, and it is those transformers that are at risk. If the geomagnetic storm is large enough, the induced currents can melt the transformers.
A real threat
One of the strongest major storms in recent memory occurred in March 1989. Over a period of several minutes, the Hydro Quebec power grid in eastern Canada collapsed and 6 million customers lost power. The blackout lasted almost nine hours and caused an estimated C$2 billion in economic losses—and it could have been worse. The effects almost cascaded to regional power grids, which could have blacked out the Northeast and mid-Atlantic regions of the U.S.
Scientists and power grid operators worry about the prospect of something much larger, and such an event would not be without precedent.
Over the final days of August and first days of September 1859, an extreme solar storm occurred that ranks as the strongest ever recorded. It enabled amateur astronomers to make the first-ever observations of solar flares, and such giant storms are now named after one of those astronomers, Richard Carrington.
The Carrington event was so strong that aurorae, usually confined to the far north, could be seen in the night sky as far south as the Caribbean. Electricity still wasn’t widely in use, but the storm shut down parts of the international telegraph network. In some places, telegraph lines were reported to be sparking, and The New York Times reported from Montreal that the Canadian Telegraph Co. took five hours to send a 400-word report because of the bad conditions.
“So completely were the wires under the influence of the Aurora Borealis, it was found utterly impossible to communicate between the telegraph stations, and the line was closed for the night,” the newspaper reported on Aug. 30, 1859.
Historical records suggest Carrington-level events occur every 50 to 250 years, so Earth is now at the 150-year sweetspot for a repeat.
A recent report by Lloyd’s of London predicted that another Carrington-level event is “almost inevitable in the near future” and paints a concerning picture of its potential effects. Should the U.S. be hit head on by such a storm, the report says, 20 million to 40 million people could be left without power for anything between 16 days and two years. The recovery time is so long because high-voltage transformers are such specialty items. Power utilities don’t keep spare ones lying around, and they take up to 16 months to build.
The economic impact of such an event could be as high as $2.6 trillion, the Lloyds report said.
Staving off an economic threat
The power industry isn’t ignoring the threat. An April 2011 workshop between electricity grid operators from the U.S. and Canada resulted in the creation of a space weather alert system for the industry, and plans for coordination should a major geomagnetic storm be detected. Grid operators would have between 15 hours and two days to prepare for the storm by increasing reserves, reducing power transfers and lightening the load on susceptible equipment.
But any reduction in the availability of power could itself have an economic impact, so it’s a situation to be avoided unless the likelihood of serious damage to the power grid is high.
Learning more about the sun’s weather can only help scientists to provide warnings for such events.
“What we don’t know is how it works, what in detail it will damage, or how likely it is that that damage will spread,” Schrijver said. “And the difficulty with it is that these things happen only rarely. Once a century is when a really big solar event occurs, and our technological infrastructure has changed so much, we’ve never been exposed to it.”
Updated at 12:20 p.m. PT with a video report from IDG News Service.